2W5V image
Deposition Date 2008-12-15
Release Date 2009-11-24
Last Version Date 2024-11-20
Entry Detail
PDB ID:
2W5V
Keywords:
Title:
Structure of TAB5 alkaline phosphatase mutant His 135 Asp with Mg bound in the M3 site.
Biological Source:
Source Organism:
Host Organism:
Method Details:
Experimental Method:
Resolution:
1.78 Å
R-Value Free:
0.19
R-Value Work:
0.15
R-Value Observed:
0.16
Space Group:
P 21 21 2
Macromolecular Entities
Polymer Type:polypeptide(L)
Molecule:ALKALINE PHOSPHATASE
Gene (Uniprot):phoA
Mutations:YES
Chain IDs:A, B
Chain Length:375
Number of Molecules:2
Biological Source:ANTARCTIC BACTERIUM TAB5
Modified Residue
Compound ID Chain ID Parent Comp ID Details 2D Image
SEP A SER PHOSPHOSERINE
Primary Citation
Coordination Sphere of the Third Metal Site is Essential to the Activity and Metal Selectivity of Alkaline Phosphatases.
Protein Sci. 19 75 ? (2010)
PMID: 19916164 DOI: 10.1002/PRO.284

Abstact

Alkaline phosphatases (APs) are commercially applied enzymes that catalyze the hydrolysis of phosphate monoesters by a reaction involving three active site metal ions. We have previously identified H135 as the key residue for controlling activity of the psychrophilic TAB5 AP (TAP). In this article, we describe three X-ray crystallographic structures on TAP variants H135E and H135D in complex with a variety of metal ions. The structural analysis is supported by thermodynamic and kinetic data. The AP catalysis essentially requires octahedral coordination in the M3 site, but stability is adjusted with the conformational freedom of the metal ion. Comparison with the mesophilic Escherichia coli, AP shows differences in the charge transfer network in providing the chemically optimal metal combination for catalysis. Our results provide explanation why the TAB5 and E. coli APs respond in an opposite way to mutagenesis in their active sites. They provide a lesson on chemical fine tuning and the importance of the second coordination sphere in defining metal specificity in enzymes. Understanding the framework of AP catalysis is essential in the efforts to design even more powerful tools for modern biotechnology.

Legend

Protein

Chemical

Disease

Primary Citation of related structures